1. Field of the Invention
The present invention relates to a scanner apparatus for scanning sheets such as personal checks, and relates to a multifunction device such as a check processing system having a sheet scanner and a print head for printing on the sheets.
2. Description of the Related Art
Multifunction devices have been developed that can be used for more than one task by combining a printer, which is equipped with a print head, with a scanner or other such processing device, for example. A multifunction device so equipped with a print head and scanner can be used to print required information on the check, scan and capture an image of the printed check, and send the scanned image to a bank or other financial institution, as necessary, thereby enabling on-line settlement of check transactions using digitized transaction content data.
There are two types of scanners used in such multifunction devices, ones that scan with the sheet (check) stationary, and ones that scan while the sheet is conveyed passed the scanner. This latter type typically has a feed roller disposed opposite the scanning position for transporting the sheet while pressing it against the scanner.
A problem with scanners having this type of pressure feed roller is that when the edge of the sheet enters between the scanner and pressure feed roller, jams can result if the paper catches. The likelihood of jams occurring increases particularly when the sheet is in poor condition (such as being curled, creased, or torn).
Furthermore, if the leading edge of the sheet reaches the pressure feed roller before another operation is completed (such as printing or MICR reading) and the feed pitch is shifted as a result of the sheet being caught by the roller, the precision of the other operation will drop and the operation may not be completed normally.
A further problem is that when such a feed roller is used, the roller directly contacts the reading surface (a scanning glass, for example) of the scanner after sheet transportation is completed, potentially increasing the drive load. When it is necessary to scan to the trailing edge of the sheet, it is particularly difficult to prevent the feed roller from directly contacting the scanning glass surface. Damage to the drive power source and transfer gears as a result of overloading is therefore possible. If a stepping motor is used for the drive power source, an overloaded feed roller can also cause the stepping motor to skip, producing undesirable noise.
The present invention is directed to solving these problems, and an object of the invention is to provide a multifunction device which, while having a pressure feed roller opposite the scanner position for conveying a sheet while pressing the sheet against the scanner, avoids the sheet being caught by the pressure feed roller and can thereby prevent jams and skips in the feed pitch.
A further object of the invention is to provide a scanner apparatus which, while having a pressure feed roller opposite the scanner position for conveying a sheet while pressing the sheet to the scanner, can automatically retract the feed roller from the scanner based on the feed roller drive load and thereby eliminates such problems as damage to the drive source and transfer gears, skipping of the stepping motor, and abnormal undesirable noises resulting from an increase in the drive load when the feed roller directly contacts the scanning glass surface.
To achieve these objects, a multifunction device according to the present invention has a transportation path for guiding a sheet; a print head positioned along the transportation path for printing on the sheet; a scanner head positioned along the transportation path for scanning the printed side of the sheet; a pressure feed roller positioned opposite the scanner head for transporting the sheet while pressing the sheet against the scanner head; and a roller retraction mechanism for retracting the pressure feed roller from the scanner head and opening the transportation path.
The trailing end part of the sheet that is ejected by the pressure feed roller is preferably held within the vertical part the transportation path downstream from the pressure feed roller. Because the ejected sheet is thus held using the transportation path itself on the downstream side of the pressure feed roller, the number of parts can be reduced and the construction simplified compared with configurations having a special form holding member.
Further preferably, a focusing position of the scanner is offset to the upstream transportation side or downstream transportation side from a position of the scanner head that contacts the pressure feed roller. Pressure from the pressure feed rollers is thus prevented from being applied directly to the focusing position of the scanner head. This reduces the likelihood of ink being transferred and adhering to the focusing position in the scanning process after printing, and prevents as much as possible loss of quality in the scanned image due to such ink. In addition, if the offset is to the downstream side, the scannable area at the leading edge side of the sheet can be increased.
Yet further preferably, the roller retraction mechanism comprises a roller support shaft for supporting the pressure feed roller; a rotating member for advancing and retracting the roller support shaft toward and away from the scanner head; an urging member for urging the rotating member toward the scanner head; a solenoid for retracting the rotating member against the urging force of the urging member; and a drive mechanism positioned near the rotating member for driving the pressure feed roller. By thus supporting the pressure feed roller so the rollers can be freely advanced and retracted by the pivoting rotating member, the roller retraction mechanism can be compactly constructed, the rollers can be smoothly advanced and retracted, and drive power can be reliably transferred to the pressure feed roller because the drive mechanism for driving the pressure feed roller is positioned near the rotating member.
Yet further preferably, the rotating member is positioned between the pair of pressure feed rollers supported on the roller support shaft. The pair of pressure feed rollers is thus substantially uniformly urged, preventing form feeding problems due to differences in roller pressure. The transportation path can also be reliably opened because when the rollers are retracted both pressure feed rollers move in parallel.
Yet further preferably, the pressure feed roller and roller retraction mechanism are positioned in a scanner feed unit that is separate from the scanner head, and the complete scanner feed unit can be retracted from the scanner head. A wide space between the scanner head and pressure feed roller can thus be opened by retracting the entire scanner feed unit, making it easy to remove paper jams in the scanning area and making it easy to clean the surface of the scanner head.
Yet further preferably, a platen is positioned in the scanner feed unit opposite the print head. A wide space is thus also opened between the print head and platen in conjunction with retracting the scanner feed unit, making it easy to remove paper jams in the printing area.
Yet further preferably one of the feed roller pair disposed upstream of the scanner head is also included in the scanner feed unit. A wide space is thus also opened between the feed roller pair in conjunction with retracting the scanner feed unit, making it easy to remove paper jams in the feed rollers.
Further achieving the above objects, a scanner apparatus according to the present invention has a transportation path for guiding a sheet; a scanner head positioned along the transportation path for scanning one side of the sheet; a pressure feed roller positioned opposite the scanner head for transporting the sheet; a rotating member supporting the pressure feed roller and enabling the pressure feed roller to be advanced toward and retracted from the scanner head; an urging member for urging the rotating member toward the scanner head; and a roller drive mechanism for transferring drive power to the pressure feed roller. The roller drive mechanism moves the rotating member in the retraction direction according to a driving load applied to the pressure feed roller.
Preferably, the roller drive mechanism has a motor; a feed roller gear rotating integrally with the pressure feed roller; a sun gear rotated by drive source power of the motor; and a planetary gear freely rotationally supported on the rotating member and engaged with the feed roller gear and sun gear. The roller drive mechanism can thus be configured with the fewest parts, thereby contributing to a reduced part count and a simplified configuration.
Yet further preferably, the scanner apparatus comprises an upstream-side feed roller positioned on the upstream-side of the pressure feed roller. The pressure feed roller being driven with a peripheral velocity higher than the upstream-side feed roller. This applies appropriate tension to the sheet and prevents jams and scanning errors due to slackness in the sheet. Furthermore, problems such as applying excessive tension to the sheet or the drive source being overloaded are also prevented because the drive load of the scanner feed roller is controlled automatically by the roller drive mechanism.
Yet further preferably, at least one pair of the pressure feed rollers is supported on a feed roller support shaft, and the rotating member is positioned between the pair of pressure feed rollers. The pair of pressure feed rollers can thus be advanced and retracted substantially in parallel, and problems such as skewing the sheet due to variations in the form transportation force can be avoided.
Yet further preferably, the rotating member comprises a paper presser guide for aligning the sheet with the scanning surface of the scanner head. Floating or drifting of the sheet between the pair of pressure feed rollers is thus restricted and scanning accuracy can be improved.
Yet further preferably, the scanner apparatus also has a solenoid for forcibly rotating the rotating member in the retraction direction so that space between the pressure feed roller and scanner head opens and closes according to solenoid drive. The sheet can therefore be prevented from catching in the pressure feed roller by driving the pressure feed roller solenoid to open the transportation path when a sheet is advanced between the pressure feed roller and scanner head. The total part count can also be reduced and the configuration simplified because the transportation path can be opened and closed using the mechanism (including the rotating member) for retracting the feed rollers according to the drive load.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.